1. Field of the Invention
The invention relates to a wireless terminal comprising a camera, more particularly, the wireless terminal that can quickly display a zoomed picture with a desired scale factor.
2. Description of the Related Prior Art
In late years cellular telephones with a camera spread rapidly. This camera comprises electronic zoom function rather than optical zoom function, because a housing of the cellular telephone has to be made thin as possible. Japanese Patent Laid-Open No. 2002-077698 bulletin discloses an example of a method to zoom in or zoom out a picture by means of an electronic zooming.
In an electronic zooming method, there are a method carried out by software and a method carried out by hardware. The electronic zooming method carried out by hardware performs cutout and pixel skipping of a picture. The method enables to form a picture with a normal scale factor and pictures with some fixed scale factors. However, a picture of an arbitrary scale factor cannot be formed. An operator, therefore, must change distance between a camera and an object to get a picture with a desired scale factor. The electronic zooming method carried out by software enables smooth zooming in small steps. However, as the number of the pixels of the picture increases, time to need for zooming increases. Particularly, it becomes difficult to display a picture with a desired scale factor when speed of zooming rises.